/in/foo.cc: In function 'int main()':
/in/foo.cc:42:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  while(i<r.size()||j<b.size())
        ~^~~~~~~~~
/in/foo.cc:42:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  while(i<r.size()||j<b.size())
                    ~^~~~~~~~~
/in/foo.cc:48:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    while(r[i]==flag&&i<r.size()) i++,sumr++;
                      ~^~~~~~~~~
/in/foo.cc:49:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    while(b[j]==flag&&j<b.size()) j++,sumb++;
                      ~^~~~~~~~~